Electric heater



c. SYKES ET AL Feb, 15, 1938.

' ELECTRIC HEATER Filed July 16, 19:57

Inventors Charles Sykes;

WilliamNeed aim, IV a.)

Th aw Attowfng.

I Patented Feb. 15, 1938 UNITED; STATES amc'rnrc rms'rsa Charles Sykes,'limperley, and William Needham, Sale, England, assignors to GeneralElectrio Company. a corporation of New, York Application Ill, 18, 1987,Serial No. 154.107

- 1!! Great Britain In]! 2'1, 1936 This invention relates to electricheaters. more particularly to terminal boxes for electrical heat- 'ingdevices for cooking stoves, for instance hot plates in which the heatingelement comprises a .wire embedded in insulation, the ends of theheating elements being joined to supply leads within the box and the boxsupported by the body of the stove, for instance by hinging. Insuchconstructions the insulation in which the wire is embedded must beprotected from moisture otherwise serious deterioration may occur.Usually the body of the heating element is adequately protected bysheathing or by being embedded in a heating plate. It is still, however,

desirable to ensure that split liquid shall not reach the ends of theinsulation at the point of juncture of the heating element with thesupply leads, which point is located within the terminal box. It is alsodesirable to provide an air space about the joints between the heaterelements and the supply leads.

According to the present invention a terminal box for a heating devicefor a cooking stove is formed with a joint chamber adapted to house thejoints between the heating elements and the supply leads, boresextending upwardly from said chamber for \accommodating the ends of theheater elements, a chamber intended to be packed with a filling to sealthe supply leads. which chamber is located to one side of said jointingchamber and has openings in the walls through which the supply leadspass to the jointing chamber and a detachable side to said terminal boxwhich side acts as a closure to the joint cham- -ber and to the upwardlyextending bores, the jointing surface between said side and the body ofsaid terminal box intersecting the bores longitudinally. I

when embodied in a heating device for a cooking stove the joint chamberforms an air space about the joints between the heater element orelements and the supply leads and the heater element or. elementaformwith said upwardly extending bores a seal against the entry 5 ofliquidand the sealing chamber is packed with asealing material such ascement to prevent the ingress of moisture to the joint chamber along theends of the supply leads.

Preferably the joint chamber ;is vented. in such a case however the ventmust be located underneath so that it does not allow moisture to enter.

Fora more complete understanding of this invention, reference should behad to the accompanying drawing in which Fig. 1 is a sectionalsideelevationofaterminalboxembodyingthis invention; Fig. 2 is a frontelevation of the terminal box of Fig. 1; Fig. 3 is an outside sideelevation of the terminal box as shown in Figs. 1 and 2, but beforeincorporation in a heating device; and Fig. 4 is a plan view of theterminal 5 box as shown in Fig. 3. In the drawing,'the reference numeralI indicates the body of the terminal box and I the cover whilst I is thejoint chamber. The heater elements of which there are two, their sheaths10 beingindicated by the references 14 and I respectively, extendupwardly fromthe jointing chamber through bores I formed in an extendedupper part I oi the terminal box. The sheaths of the heater elementsform a liquid-tight joint with is I the bores I and to this end they maybe soldered or brazed.

The supply leads Ia are joined to the heater elements within thejointing chamber I. as illustrated in Fig. 1 in the case of the heaterelement 20 In. From the jointing chamber the leads la pass laterallythrough apertures in a wall I and through apertures I in a wall II;collars ll protecting the leads at the points they pass through theseapertures.

Between the walls I and N there is formed a sealing chamber II which ispacked with a filling of cement or other suchrnaterial so that itprovides a liquid-tight seal around the leads. The sealing chamber II isclosed by a cover plate'iI 30 held in place by screws.

- The detachable side I of the terminal box is located in the oppositeside to that at which the supply leads enter and itwill be observed thatthe jointing surfaces iI intersect the bores I 35 longitudinally, thusthe side 2 acts as a cover both for the jointing chamber 2 and also forthe portions of the heater elements located in the bores I. The side Iis held in place by screws. The body portionof the terminal boxoverlying 40 the chamber II is formed with ribs II to assist inpreventing liquid split on the'terminal box from running down on to thesupply leads. II are pivots for hinging the box on to the frame ofacooking stove.

While we have shown a particular embodiment of our invention, it will beunderstood, of course,- that we do not wish to be limited thereto sincemany modifications may be made, and we, therefore, contemplate by theappended claims to cover any such modifications as fall within the truespirit and scope of our invention.

What we claim as new and desire to secure by letters Patent of theUniiedStates. is:

1. In a heating device for a cooking stove hav- 66 ing heating elementsand supply leads, a terminal box formed with a joint chamber adapted tohouse the ioints between the heating elements and the supply leads, andhaving bores extending upwardly from said chamber for accommodating theends oi the heater elements to admit them to the joint chamber, a secondchamber intended to be packed with a filling to seal the supply leads,the. second chamber being located at one side of said Joint chamber andhaving "an opening or openings in the walls through which the supplyleads pass to the joint chamber and a detachable side to said terminalbox which side acts as a closure to the Joint chamber and to theupwardly extending bores, the jointing surface between said side and thebody of said box intersecting the bores longitudinally.

2. In a heating device for a cooking stove having heating elements andsupply leads, a terminal box formed with a joint chamber adapted tohousethe Joints between the heating elements and the supply leads, and havingbores extending upwardly from said chamber for accommodating the ends ofthe heater elements to admit them to the joint chamber, a second chamberintended to be packed with. a filling to seal the supply leads, thesecond chamber being located at one side of said Joint chamber andhaving an opening or openings in the walls through which the supplyleads pass to the Joint chamber and a detachable side to said terminalbox which side acts as a closure to the Joint chamber and to theupwardly extending bores, the jointing surface between said side and thebody of said box intersecting the bores longitudinally and the Jointchamber providing an air space about the Joints between the heaterelement or elements and the supply leads, the ends oi the heater'elementor elements passing to the Joint chamber downward- 'ly through theupwardly extending bores, liquid-

